Arc-welding apparatus



Sept. 18,1923. 1,468,156

J. A. HOLIFIELD 1 ARC WELDING APPARATUS Original Filed May 9. 1921 ATTORHEY Patented Sept. 18, 1923.

UNITED STATES PATENT FFICE.

JOSEPH A, HOLIFIELD, OF MOBILE, ALABAMA. .ASSIGNOR TO WHITE FUEL OIL EN- GINEERING CORPORATION, OF NEW YORK, N. Y., A CORPQRATIUN 0 NEW YORK.

ARC-WELDING APPARATUS Application filed May 9, 1921, Serial Ta all iii/tom it may coiwern: t Be it known that l. Joel-1H1 A. l'll'lLlFllGLl), a citizen of the United States of America, residing at Mobile. in the county of Mohile and State of Alabama. have invented certain new and useful Improvements in Arc-\Velding Apparatus, of which the following is :1 Specification. 7

This invention relates to an arc welding apparatus and contemplates certain modifications in the design and operation of the arc welding system utilizing a twin field type of self-regulating generating apparatus for the Welding current, which forms the subject matter of my pending application.

Serial No. 454.277, filed the 21st day of March. 1921, wherein I disclose an armature having a single eoi'omutator and twin inde pendmit of fields separately and litferentially excited which are adapted simul taneously and jointly to exert the sum of the ijlitl'erence of their magnetic iritluenws upon the same windings of the armature to both generate and automaticallr regulate the current delivered to the welding" circuit to maintain a suhstantially emistimt wattage or current at the are.

The object of my present invention is to provide the set of fields. whose magi'ietiu in fiuencc varies responsive to the resistance in the arc, with compound dilterentiall connected windings to the end that hetorc the are is struck both sets of fields will have like polarity and exert aoeumulatively the sum of their magnetic influence on the arrna turn so as to give it a high voltage under such open circuit conditions. When the urn is struck. the flow oi the welding current; will reverse the polarity of the variable not, of fields and at the same time short circuit. the terminals of the accumulative windings thereof so that the twin set-s of fields now act differentially. the one set opposing the other with the result that lhe magnetic influence of the twin fields on th armature now is the SUM! of the differenc oi thrir magnetic strength. he ailrantag'e of the higher voltage under open arr eoi'nlilions with h lh hl'lm t' ilt lf tli' ting); at" nn'iilntirel is that hen thi- Lli'l' if trurlt it wzl spond more ins thiing function oi ASillUrIllzltlM i rying my preseoi reference is made preferably designed with n the independent sets of poles hot this is No. 4674844. Renewed June 29 1 323 ,Lllttllltllillltf drawings which f rm a part of this specification. and in win nhown a shaft 1 driven by any soitahie source, of power and having mounted thereon an ar mature L. This :Hllliii are is elongated to p rmit of its co-operatiim nith tw n parallel nets of fields 3 and -l whiuh are independent of each other and which hoih exert a joint magnetic influence at the sam tinoupon the same coil of the armature windings trpi rally illustrated at :3. The armature coil is gap ti hetueeu merely a preterahle design and is n t essential. Current from any snhslanliallv t'llllstunt. potential direct (Illi ll source mi plied through circuit 1 tothe held windings 5 SllllOllJl llllL" the ct oi poles thu sup nratelv l.(('lllll; this set oi held with a constant l'nitential current and giving; them a constant polarity and a nl mianliallv e'onstant inagnutie strength The generator is provided with any nlliiillill l type ol' roinuuitator 11 connected in :zuv vustouiarv man her with the armatuw windings 3 and having it lirushcs it r om-civil in Fll'llw with the wi-hlin :mi'iri'uit 13 whi h includ s the electrode ll and if and has in eries there with the other set ol' lii-ld c i s l surroundinn the poles lllv The twin parallel li llli Ii and 4 are wound to lune under \velilin; on-- ditions. opposite polarity and they are. so wound that the constantly excited lltlllH will have, a predominating magnetic inlllltllt't on the armature which is opposed more or less according to the resistance, in the are hy the magnetic intluencc oi" opposite polarity of the series liehh. with the r sult that the generator will aulomalii'allv indu e a prcdeterniineil tlow of current through the are, circuit 13 which iin proportion to the rerpiireniculs at the arm my in ther word the sum of tho joint cll'ci-l ol' llHll magnetic. influences. on t'llllllll ll armature windings is to gem-rate current uhivh ail maintain llawattage Hilistanlinlli con iunt ill, the are throiu hout its lastic, limits.

l Provide a ditl'w' utial "ano r l windmt l: l] the in? l polis iii Min ing do: in

voltage of the generator will be increased. As soon :18 lhc arc is struck and the current llow couuncnccs through the fields l. the circuit lb will be practically short circuited and the How of current through the fields -l will reverse the polarity of the poles 16 so that their magnetic influence now will oppose or buck that. of the fields 3 and the voltage of the machine drops hut. the current output is in proportion to the sum of the difference of the magnetic influence of the fields 3 and l and will supply a suhstzuu tiully uniform current at the arc within its elastic limits. I i

In operation, with the are circuit open and the constant exciting current following through the fields 3, the fields 4 will be open circuitcd and current will flow through the circuit 18 and through the differential field windings l7 changing the polarity of the fields 4 so that they will act collectively with fields 3 and thereupon the generator operates with the sum of magnetic influence with hoth sets of fields co-operating to induce a high voltage current. Immediately on striking the arc, the current 18 is short circuited and the flow of current through the field coils 4 will reverse the polarity of said fields and set up an opposing or bucking current in the armature windings so that the cur-- rent output is equal to the sum of the dillerence between the magnetic influence of the twin sets of poles or to the preponderance of the magnetic intensity of the constantly excited set of fields 3 over that of the set of fields 4. As the are is drawn, the resistance in the arc circuit increases and as a result the predominance of the fields 3 will proportionately incrcusc over the fields 4 with u rcsultnnt proportional increase in the volt-. age of the current in the arc circuit and :it the Mill)? tiluc, us thc resistance in the urc circuit increases. the field windings l7 hc olne stronger and h hucking the windings 4 will lurlhcr increase the predominance of the fields t and further incrcuse the voltage of the currcut output. As a result of this opcratimi, thc generator will unto umticnlly produce in the arc circuit :1 current flow which will be substantially c0nstant at the are or which will maintain the wattage at the are substantially constant within the normal elastic limits of the arc.

Having thus described my inventiom what I claim as new and desire to secure by Letters Patent, is:

In an arc welding; apparatus, an armature having a single cmumutator, brushes for the commutator, an arc welding circuit in series with the brushes, twin fields for the armature, a separately excited winding for one set of fields giving them a constant p0- larity and a substantially constant magnetic strength, and compound difi'erentislly connected windings for the other set of fields one winding in series with the are and the other in a circuit across the brushes.

In testimony whereof I affix my signature,

JOSEPH A. HOLI FIELD.

Witness I Noun: WELSH. 

